Generally, a planar solid electrolyte fuel battery (also referred to as a solid oxide fuel cell (SOFC)) is composed of a plurality of planar cells, as a power generating element, each composed of an anode (a negative electrode), a solid electrolyte and a cathode (a positive electrode), and a separator (also referred to as an interconnector) arranged between a plurality of cells. The separator electrically connects a plurality of cells to one another in series and is arranged between a plurality of cells in order to separate gases supplied to each of the plurality of cells, specifically in order to separate a fuel gas (e.g., hydrogen) as an anode gas supplied to an anode from an oxidant gas (e.g., air) as a cathode gas supplied to a cathode.
Conventionally, the separator is formed of conductive ceramic materials such as lanthanum chromite (LaCrO3). When the separator is formed by use of such a conductive material, it is possible to make a member serving a dual function in the above-mentioned electrical connection and separation of gas by one material.
For example, WO 2008/044429 A (hereinafter, referred to as Patent Document 1) discloses a structure of a solid electrolyte fuel battery.
A solid electrolyte fuel battery disclosed in Patent Document 1 includes an intercellular separation part disposed between a plurality of cells, each of which is composed of a fuel electrode layer (anode layer), a solid electrolyte layer and an air electrode layer (cathode layer), and a gas passage structure part having a fuel gas passage for supplying a fuel gas to each cell and an air passage for supplying air to each cell. The intercellular separation part, the gas passage structure part and the cell are integrally formed. Since a main body of the gas passage structure part serving the function of a manifold is composed of an electrically insulating body forming the intercellular separation part serving the function of a separator, and the gas passage structure part and the electrically insulating body forming the intercellular separation part are continuously formed, a portion serving the dual function of a separator and a manifold is continuously formed.
Patent Document 1: WO 2008/044429 A